There is, they say, nothing new under the sun. Or under the stage-lights, too, it seems. Francis Beaumont’s pioneering comedy plays with all sorts of meta-theatrical tricks that we think of as avant-garde: deconstruction, juxtaposition of styles, blurring of “real” and “fictitious” worlds, focus on actor-audience interplay as the key to drama. Only it was written 400 years ago. As such it presents a great opportunity to test out the Sam Wanamaker Playhouse as a venue for comedy. The good news is that the intimate, candlelit theatre proves a convivial space, ideally suited to experimental theatrical mischief and banter between stage and auditorium. The less happy news is that the play, for all its fascinating innovations and despite an enjoyably inventive production directed by Adele Thomas, is slightly harder work than you might hope.

The premise is excellent. The actors embark on a stock drama about thwarted lovers, but are rudely interrupted by a couple in the audience who demand something more populist. A grocer (Phil Daniels) and his wife (Pauline McLynn), these two are the classic audience nuisances that we all know and shush: they rustle about in bags, eat sweetmeats loudly and comment on the action. They don’t send texts on their mobile phones, but only because an accident of birth has landed them in the pre-digital era. They then hijack the production, insisting that the company incorporate a chivalric romance performed by their beloved apprentice, Rafe. Thus the long-suffering actors try to accommodate Rafe’s damsel-rescuing exploits into their increasingly ragged plot.

Much comedy arises from the clash of dramatic styles, the company’s irritation and the oblivious delight of the grocer and his wife. Their reaction, ironically, becomes the real substance of the drama. And there are some serious – and still resonant – questions here: who is theatre for, who is it about and who calls the shots? Beneath all the mayhem, the gawky Rafe (Matthew Needham) touchingly begins to blossom in confidence as he performs.

Remarkable, groundbreaking stuff, then, though at three hours the play rambles on too long and the jokes and joviality begin to wear thin. But Thomas’s sprightly staging serves it handsomely, filling the compact theatre with daft gags, knockabout fights and delightful performances. Dickon Tyrrell shines as an absurd suitor decked out in peach breeches and doomed to speak in rhyming couplets, as does Paul Rider as a ridiculously optimistic old crooner, while McLynn, as the earnest, busybody Wife, is a joy.